Need Help fixing power supply

[skywalker999]

ok guys need help here i have these two pansat 2500 clones or pantecs
here is the problem the two power supplys have the same problem
the output voltage is hire or lower dan what it supose to be here is
what i'm getting

normal ---------output i'm getting

+5 V ---------------+7.2 V
GND -----------------GND
+12 V--------------+11.9 V
+3.3 V-------------+2.6 V
+3.3 V-------------+2.6 V
+5 V---------------+7.2 V
GND---------------- GND
+20 V--------------+26.9 V
+30 V--------------+42.1 V
GND-----------------GND
+3.3 V-------------+2.6 V

any help would be greatly appreciated these receivers are used for pure fta 97 west thanks

[Costactc]

The GND and +5V on the back of your receiver shouldn't have anything to do with your power supply. Those are used for flipping polarity between V/H when a servo motor is attached to your feed. It will not have any effect on a stationary or motorised setup when watching true fta channels.

[Nostradamus]

not trying to be disrespectful really but if I were you I would just trash them and pick up something else at a yard sale or flea market. Lots of old boxes around and considering those were only about $75 8 years ago hardly worth the effort of knocking yourself out over. :)

[Costactc]

not trying to be disrespectful really but if I were you I would just trash them and pick up something else at a yard sale or flea market. Lots of old boxes around and considering those were only about $75 8 years ago hardly worth the effort of knocking yourself out over. :)

Still a great receiver if sd is all that you want to see. I still use my Pansat 2500 outdoors for dish installs and or skewing my feed.

[skywalker999]

i know its not worth the time to fix these receivers but i like to play around with them and i know that i can still by one of these at my local electronics store for 47 dollars plus tax but i like the challenge some are very easy to fix like a blown cap but my question was what is causing the power supply to give a hire voltage or lower example instead of +5 volts i.m getting +7.2 volts

[Nostradamus]

that voltage directly off the supply or being measured someplace on the board? Right off the supply and it would have to be some kind of a short in the windings on the transformer would be my guess. If you are getting those voltages from a test point on the board then it sounds like some other component in between has gone fubarred

[steven charles]

ok guys need help here i have these two pansat 2500 clones or pantecs
here is the problem the two power supplys have the same problem
the output voltage is hire or lower dan what it supose to be here is
what i'm getting

normal output i'm getting

+5 V +7.2 V
GND GND
+12 V +11.9 V
+3.3 V +2.6 V
+3.3 V +2.6 V
+5 V +7.2 V
GND GND
+20 V +26.9 V
+30 V +42.1 V
GND GND
+3.3 V +2.6 V

any help would be greatly appreciated these receivers are used for pure fta 97 west thanksfriend if i were you and you just want true fta channels,i would just get a coolsat 4000,5000 or 6,000 there great for true fta channels,and you can get one on ebay for around 50 bucks....

[skywalker999]

yes it's been measured from the output cable that connects to the receivers mother board but if you say that it could be the transformer then forget it maybe your right its not worth repairing o well a hobby is a hobby

[Terryl]

yes it's been measured from the output cable that connects to the receivers mother board but if you say that it could be the transformer then forget it maybe your right its not worth repairing o well a hobby is a hobby


Is that with it plugged into the mother board?

Or disconnected from the mother board?

If disconnected from the mother board then you may read a higher then normal voltage, as you don't have the proper DC load on the circuit.

If a DC power supply was designed to deliver 12 volts DC at 1 amp into a 200 ohm load, and you remove the load you will get something other then 12 volts DC, usually a higher voltage.

[skywalker999]

the measurements are from the cable disconnected from the motherboard and i have the same exact receiver with a good working power supply and the voltages exactly or very close to what the output is suppose to be if i swap the power supply from the good working receiver to the none working one it powers up just fine and it does not power up with the power supply that has the hire voltage why :noidea:

[edgarr]

the measurements are from the cable disconnected from the motherboard and i have the same exact receiver with a good working power supply and the voltages exactly or very close to what the output is suppose to be if i swap the power supply from the good working receiver to the none working one it powers up just fine and it does not power up with the power supply that has the hire voltage why :noidea:
It would be resisters that control the output voltage but will be hard to know what ones need replace
they can only be checked for values when out of circut

[Nostradamus]

well if not working with higher voltages the there is some type of circuitry designed to shut down and prevent damage to other components if the voltages go too high. Only makes sense really as most of those ICs are quite delicate and extra power would toast them

[bkr™]

I tossed my 2500 and my flu's long ago even though they worked great, however sounds like a zener diode or voltage regulator in the circuit has let go, now I wish I had one back to just play with. sorry

[Terryl]

Is this a switching power supply? (no big boat anchor of a transformer)

Or an old style analog power supply, with a big heavy transformer?

If it's a switching power supply it is FUBAR.

If analog you may be able to fix it, but it would be much much much easier with a schematic to trouble shoot it, guessing at whats what is no way to fix it.

[pcman]

Your only chance is to find a supplier that can sell you the whole supply or a kit for that the 2500 ! the ic in it regulates the voltages ,it contains caps,resistors,and zener diodes which all 3 can cause a lower or higher voltage.I not fixed these but have done all direct and dish. You can fix them if you locate the part # on the part or sometime it is on the board but it is hard to do and there always is mutiple problems depending on what caused it .A common short or overload somewhere is not bad lightening is worse .

[Limon]

According to the circuit diagram there is no 5v rail, the 7v you are reading is correct.
18372

[Terryl]

After looking at the schematic, that is a switching power supply, if you have never worked on one before then don't, there are some VERY LETHAL high frequency AC voltages in there, (on the input side) it can knock you up against the wall. (or worst)

We don't want to hear about any accidents.

[pcman]

Very nice power supply diagram i might need it if my 2500 ever tears .

[jvvh5897]

Yep, it is a switching power supply and those often only use one of the voltages in the regulation of all of them, so if that one voltage is off because of a bad capacitor or heavy load, then all the other voltages will read off. Typically if the supply works at all and the voltages read off, then an electrolytic capacitor is the first place to look for a fix--they dry out and go bad or overheat and distort. Not likely to be transformer.

[Limon]

In this case it's being referenced to the 3.3v rail. Check the voltage readings with the psu connected to the main board, especially the 3.3v connections. If they are way off then suspect the capacitors in that part of the circuit. If they are suspicious then replace both of them for similar values. (C11 & C12).

As already stated, be very careful before you put your hands into the unit, always disconnect the power plug from the 110 a/c supply and observe the polarity of the capacitors if you replace them.

[skywalker999]

ok guys i will try to post actual pics of the power supply's i have an original pansat 2500 and clones pansats and the power supply's are completely different

[skywalker999]

cant seem to be able to post the pics for some reason i'm having problems uploading from my laptop

[skywalker999]

ok here is finally the pics from the pansat 2500 clones and the original pany 2500
has you can the power supply from oem pany has a burned black spot that i out lined the receivers powers on but it only works for 1 minute or 2 and than no pic or video on tv has for the clone power supply i'm getting lower voltage on the 3.3 volts rail i'm getting only 2.6 volts the 12 v rail i'm getting 11.9 v witch is close and should work fine the difference from the oem pany pw and the clone is that it has two 5v rails and my voltmeter is reading 7.1v and on the good pw i'm reading 4.9v well i guess when i have more time i will try to fix them thanks


1838618387

[jvvh5897]

Discoloration like that is not uncommon in an older power board. The top of the capacitors don't look bad, but you should look at how they look next to the board too--any sign of bulging will indicate they got too hot.

[ddiirrkk]

I've run across capacitors that look fine and are still no good. The only sure way to tell is to pull them and test the with and esr meter. It power supplies this is the most common failure point.

[Terryl]

The best way to fix a suspected cap problem is to shotgun them all, replace them all with new ones.(if your going to take them out to test, why not put new ones back)

[jvvh5897]

More than likely a good idea. I had a box that would only start working after you plugged the thing in a bunch of times. I replaced a few bad looking caps in the power supply but problem was still there. An older box and not critical that it got fixed so I lived with it, but it might have been fixed if I replaced all caps. The FTA boxes can really be thought of as never intended to be worked on--they are just too cheap to replace to do more than a simple fix on them, and with a new box, you get better box features.

[skywalker999]

thanks guys for all the help best thing to do is to buy a new one i guess i have to call honer and tell him it's just cheaper to buy a new box
but when i have more time i will give it another try but i have one question about caps on the clone power supply there is a row of four black caps between the silver top ones are dose different from the radial caps

[Terryl]

4 black caps??????


More then likely those are diodes, do they have a white band on one end?

[skywalker999]

Terryl not the diodes i mean these check pic they look like caps but i never changed one of dose are they radial caps or something else

18457

[skywalker999]

re power supply anybody have a look yet

[nunoit]

ok dude those are coils used for filtering spikes in power line. (chokes) let me take a look at the pix as well as the schematic and see what i can find for you.

to let you know how that supply works is pretty simple actually the load on the 3.3v line controls how much current the rest of the fixed voltages have.

caps must be pulled to test resistors can be checked on the board unless they are in parallel to another.

now according to the diagram (schematic) the 4 caps you need to look at are c11, c12, c13,& c14. but you claim to have clone supply so follow the trace back to the transformer and check any in that line.

according to the diagram there is a 650 ohm (r13) check that resistor as it connects between the 3.3v and 7v output's

i have outlined 2 diodes check them they should be for the low voltage one for 3.3 the other 7v could be leaky or bad. diodes sometimes need to be pulled from the circuit to test.

also post pix of bottom of board please. helps in tracing circuits.

the only other thing that could cause the problem is the OPTOISOLATOR circuit which has a cap resistor oscillator which if the resistor or the cap are weak the supply will fail to work.

the way that works is when the current draw on the3.3v line drops from demand it changes the resonant frequency of the oscillator which gives the optoisolator the signal for the supply to add more power to the transformer to compensate for the draw in current on the 3.3v line and also the rest of the supply.

now you probably did not need to know all that that's just fyi for those that want info on switching power supply's. i have repaired them before.

that's enough info for now check that first. nunoit

[skywalker999]

Thanks nunoit that is exactly my next step i have tested them just to see what was the output voltage coming from dose diodes with power turn on i connected my voltmeter negative ground to the chassis and with the positive i touched the output of all the diodes next to the two that you have outlined for me the voltage coming out of them they are exactly the same i'm getting at the end of the cable so dose that mean that the diodes that are giving hire or lower voltage are no good

ps = thanks for your reply and good info nunoit

[nunoit]

usually you don't test diodes with power on they can give you false reading. if they are in a bridge configuration you will get bad reading.

you need to do with power off check for forward, reverse polarity by using your ohms meter. put black on one side red on the other look at reading, then swap leads and read again.

a good diode will have low Resistance in one direction hi resistance in the other. {shorted will be 0000 on display open will be 1 both indicate bad.}

like i said diodes should have at least one leg removed from circuit to properly test them.

the diodes you are testing are low voltage rectifiers. common (radio crap may have them)

my suspicion is one of them is open. they can go bad and no visual sign of it.

i feel the reason you are getting the same or close to the same voltage is the resistor r13 i outlined earlier that why i said you may need to pull them off for testing.

make sure you install then correctly as they are polarity dependent. mark the the board if you have to cathode end. (the band)

[Terryl]

It's best to use a good DVM with a diode check setting on it.

And also to remeber that most diodes have about a .6 (point six) volt drop across them, so if the desired voltage on the output side is 12 volts DC, then the diode will have at least 12.6 volts (or more) on the input side, any less and it may not turn on, or the desired voltage at the output side will be lower then expected.

Too bad the schematics don't have tech notes to follow for troubleshooting, also waveforms for use with an oscilloscope, that would tell you right away what cap was bad and what diode was funky.

If your in a hurry to fix this then I would just start shotgunning parts, (replacing one whole section at a time with new) as you could be at this for a bit.

But if you have the time then this will be a good learning curve, and some good technical experience.

If you knew the required DC current load for each voltage buss, you could build a test bed, this would save the receiver from any possible damage.

[nunoit]

Skywalker don't be afraid of this circuit, its a simple fix there just stages of testing.

i used to do and still do sometimes with old analog meter and find they work better than digital ones when it comes to testing diodes and electrolytic caps, and name brand is just that name brand.

unless your going into business in the electronics industry you don't need a 1000 dollar + oscilloscope.

true diodes have a .6v drop (or turn on voltage) and usually apply's to all voltages being applied to the device. so 2v in = 1.4v out. rectifiers have a max voltage (or piv)that can be applied and since we are not playing with zener diodes we don't need to know input voltage.

rectifiers take ac turn into dc. so there will be no dc on one side (anode side) of the diode under test.

if i were you i would just pull one leg and test. easiest thing to do.

all you need to do is learn how to understand what the circuit is telling you, by what is not doing is where you need to look.

your not getting low control voltage so look there. you don't take aspirin for a stomachache.

if your going to "shotgun" the parts then it would be cheaper in the long run to just buy a new power supply and save the time and learning experience.

please post your results interested in seeing how you do.

[skywalker999]

ok Terryl and nunoit i removed one diode and two resistors from the pw supply first the diode is 1N5822 this diode my digital multimeter model MTP2325 in K oms setting it reads 50 k oms sometimes more then it sloly drops down to 34.6 if i reverse ground and positive it reads 4.5 k oms as far has i know it should read only one way not boot ways and resistor number 1 reads 3.8 koms and resistor number two anything from 5 8or 10 k oms and then very quickly drops to four zeros in less then a second here are the pics of the diode and resistor that i removed and the pic from the back side that nunoit asked me for remember i'm in no hurry to fix this receiver has they were given to me to play with them and see if i could fix them1856318564

[nunoit]

the readings you are getting look normal multi-meters are off 1 or 2 digits actual value especially low ohm readings.

the diode reading hi ohms one way low the other is good. it shows its rectifying in one direction. if they showed the same reading or no reading in both directions that indicates they are bad.

do you know the color code you need to know what ball park value you are looking for to test resistor's the bands tell you the value. + or - 10% on most values, on less other wise marked.

caps are always 20% + or - the value marked.

i took a look at the multi-meter you have, looks to be ok, use diode test on diodes and cap test for your caps and of course ohms for resistors.

did you get a chance to check the 2 diodes i pointed out to you. one more thing can you mark on the top side pic the voltage values you measured on the out put side at or near the header. thanks

sorry if i seem to be under estimating your ability for i have no idea what that is, so i will over explain to be sure you understand what we are trying to do. if you have questions just post some one will try to explain.

[skywalker999]

no i didn't have the time to check them maybe this weekend and the resistor that gives me 4 zeros the colors are blue grey black and gold at the end and i lost the manual for my multimeter so i don't know the settings for uf to test the caps and also the diodes
so i don't know if i could find the manual online so have a good weekend i will post something new as soon as i can and thanks for your help nunoit

[nunoit]

that resistor is 68 ohm's test at 200 on your scale just google resistor calculator that will give you the value the colors indicate.

as for testing caps if i am not mistaken you wont be able to test anything over 20 uf so you wont be able to test a 200uf or 1000uf caps only low value ones like 4.7uf .

you can use the diode function to check diodes

[skywalker999]

ok i remove one of the diodes that you want me to test so diode info it's HER107 and it reads in diodes settings 0.485 and the other one with one leg disconnected from the pw supply reads 0.500 but i don't know if there's something wrong because they only give me that value with ground connected to the side of the grey marker and positive on the other side if i reverse the leads i get no value nothing and the other diode that i removed before info 1N5822 reads 0.152 so i don't know if these values are correct for these diodes now about the caps now i know why i was getting no reading from my multimeter when i tried to test a 470uf 16v

[nunoit]

the readings you are getting indicate the diodes are good. you should have no trouble reading resistors (check them). as for the caps you only have 12 so you could go head and replace all of them since you really can't check them thoroughly. (same value higher voltage is ok not lower). example 220uf at 16 ok to use 220uf at 25v if the space allows.

also can you post the number on the 2 transistor's. we can get into testing them later.

you should be able to test most components on the board. if you think the reading is to far out of spec then remove and test

[skywalker999]

nunoit today it's a good day i followed your info and after soldering back the diodes
that i had removed and changed some of the caps not all of them first receiver i only
changed the first tree caps right after the diodes and power is back to normal
and the receiver powers up and goes to channel 01 now the second receiver i changed 8 caps
then checked the voltage and it was back to normal and second receiver powers up also
here is the voltage output i'm getting now

5V rail now it's 4.7v on second receiver it's at 4.8v

3.3v now it's at 3.2v second receiver it's at 3.2v

12v now it's at 11.9v second receiver it's at 11.9v

20v now it's at 18.3v second receiver it's at 18.3v

30v now it's at 28.8v second receiver it's at 29v

thanks nunoit for all your expert help now a myth have another challenge don't know if should
try to fix this one it's another receiver with the exact same power supply but with a different
problem this one keeps blowing the fuse i already changed one diode number 1N4007 that was sending power both ways
i was reading in diode settings on multimeter 0.0001 both ways replaced with a good diode and new fuse
popped again i guess the problem is more then just that diode what do you think should hi try to fix it or not
it never hearts to learn something new lol

receiver 1
18629

receiver 2
18630
receiver3 blown fuse
18631

[nunoit]

glad you got it going.

on this one check all the diodes "important" the one right next to the transformer is a zener diode that is a special voltage regulator. (and must be replaced with the same kind)

now with that said i would suspect that the fet (field effect transistor) mounted on heat sink is bad.

also don't forget that dry or shorted caps can blow the fuse as well, there's only 2 of them to change. the large one and the one behind the heat sink.

[Terryl]

Replace the MOV on the new board that is blowing fuses first, if its bad it could short the L side to Neutral.

And why the heck did they put the fuse on the neutral side I don't know, you should always fuse the hot side, and it should be the first thing in line.

That would have never passed my desk for approval.

[skywalker999]

thanks guys let me start by explaining what i think happen to this pw supply i think it got hit by a power surge that is why it's blowing
the fuse so far i replaced the main 33uf 400v capacitor i removed lifted one leg from all the diodes and so far there is only two that are bad the one that i recently replaced and the one right next to the one i replaced the other ones tested good now how do i test that transistor screwed to the heat sink
transistor number is ( 5L0265R )
nunoit can you point out where the zener diode is the one right next to the transformer is the transformer the one on the middle of the power supply

And terryl can point or explain what is the (MOV) on the pws

[Terryl]

MOV= Metal Oxide Varistor, it acts as an inline surge suppressor, it has a turn on voltage higher then the normal expected AC line voltage, if that threshold is reached it will start conducting.

If the surge voltage is very high it will destroy the MOV, some can take several surges and not blow.

Lift one side of the MOV and see if the short goes away.
It is labled as MOV1 on the schematic.

Here is some more info on the MOV.
http://en.wikipedia.org/wiki/Varistor

[nunoit]

mov's are those little blue disk shaped things next to the main plug from the cord. and like terry said they will read shorted if they are bad and they are good they read open

have you tried since you replaced the 2 diodes to see if fuse blows. (buy extra fuses its good practice is testing.)

the (5L0265R) is like i said a fet special purpose unfortunately very hard to test. i would suggest removing and powering board with out it installed to see if fuse blows. that's a 4 pin device and needs to be tested in a special manner which requires building a test bed sort of speaking.

unless terry knows a better way the poor mans way of testing.

the transformer looking thing right next to the plug is a filter coil, the transformer is the one in the middle of the board. and almost impossible to test with out specialized tools.

[Terryl]

No way to test the FET in a non working board.

I would do as Nunoit suggested and just remove it and see if you don't blow a fuse, if you do then something else is wrong. (MOV maybe??)

If it doesn't then good luck finding the FET as that part is listed on most suppliers web sites as obsolete or at end of life.

The only place that may have it is a supplier in Asia, you could google for one.

[skywalker999]

ok guys thanks Teryl and nunoit for all the help again first nunoit i didn't soldered back the two diodes was afraid to blow them again then today went to remove that transistor and my solder sucker remover broke so i have to wait, tomorrow i have to buy a new one them china made crap
Now that i know what dose are do they come in different colors and how to test dose do i use oms or diode settings one more thing
there is a very small difference on this power supply and the one i posted this one only has one MOV (varistor) on that corner every thing else is exactly the same, can they go by name thermistor also because there is a black one right next to the fuse info (NTC 100-9)
and another thing i checked the number of that transistor on one of the two other receivers and the number is different it's a (5L0380R) that's all for now

[nunoit]

for removing parts i used to use a solder sucker now i use flux and solder wick, its braided wire made for that job. but you need to find what works best for you.

as for testing mov's use ohm's low in range, or continuity. open = good, shorted = bad. yes they come in usually 2 colors blue and black. the difference is that they are fatter than ceramic capacitors usually beige or blue in color. the part number describes its ratings.

ceramic cap's normally have number like 203, or 104 on them which indicate value. you can look up how to read them on Google. FYI your meter should be able to read those as they are low micro-farad's. BTW: there not known for going bad like other caps.

the way i test parts is i check in certain order
1 fuse's
2 diode's and transistors
3 voltage regulators
4 electrolytic caps and resistors.
5 integrated circuits
6 ceramic caps normally the last thing to go.

i go through steps 1,2,3,4, and 6 for power supply's and in order for testing main boards.

when i am changing diodes i get more than i need just in case other's blow just good practice. you can order very cheap at [ all electronics.corp ]one word for about 50 cent each.

go ahead and finish installing the diodes could be the voltage spike blue out the diodes and of coarse the fuse. most are pretty rugged for the job there doing.

when fixing a PS you need to replace and test replace and test until it's working the right way. a 50 cent fuse is cheap compared to a 50 dollar board.
if you are going to do more repairs go and buy your self a decent cap tester like HONEYTEC A6013L which reads from 20 mf to 200 pf and only cost me about 25 bucks. that way you don't have to replace caps that aren't bad.

keep us posted
Good Luck N.U.NO.IT

[skywalker999]

ok nunoit and Terryl guys today i ad some free time so i have good news and little bit of bad news so before removing the transistor
i replaced the two bad diodes closest to the fuse replaced the fuse and turned the power on and the fuse didn't blow so that's the good news now the bad news i checked the voltage output at the ribbon and all the voltages across the ribbon are fluctuating they keep going up and down constantly so I changed all the caps after the transformer
and the main big one before the transformer and it's still doing the same thing so what could be the problem now

PS; I fund the transistor on ebay and the MOV also i purchased the MOV but not the transistor

[nunoit]

first off did you test with power supply connected to the board or by itself.

now i labeled the board to what i see from the pictures.

1 OPTO-ISOLATOR
2 should be KA431
3 oscillator
4 diodes you replaced
5 3.3 volt out put leg. i may have gotten it wrong

my thoughts are that the oscillator (3) one of the 2 components are out of Tolerance. the resistor is precision ( 1 0r 2% ) and so is the cap (5 or 10%). accuracy of these components is critical or circuit acts like what you are getting.

i don't think the 5L0265R is bad for 2 reasons one the fuse did not blow and 2 the power is fluctuating. turning on and off of that device is the job of the OPTO-ISOLATOR (1) and that gets its signal from the KA431 (2) with the help of the oscillator (3)

let's see how close i am to your board

taking a closer look i see under the 2 large diodes there is resistor. also whats behind the heat sink besides the 2 caps (one round and one square) that i can see.

i think from pointer # 5, 3 pins in is the 3.3v output. if that is correct then recheck that diode if not just replace it any way. we need to eliminate all possibilities.

[skywalker999]

First I tested the power supply connected to the board receiver didn’t turn on
then I tested by itself
Next behind the transistor heat sink there’s one cap 47uf 50v one resistor color yellow brown black gold
One diode and the rectangular yellow number 100nj 100 but on the good fixed pw it’s 100nj 63
The OPTO-ISOLATOR it’s a cosmo 1010 817 A26 now the oscillator all I see on it is 105 does the oscillator go by another name what 105 means
And under the two big diodes that resistor it’s yellow brown black and gold
#5 there is no diode there it’s only one strait peace of wire that connects the 3.3 V to the 3.3V at the other end
Ok I will replace the two diodes and see if changes anything will check back tomorrow with more info and thanks nunoit

here is a bigger pic of pws link
http://picturepush.com/public/13343193]http://www5.picturepush.com/photo/a/13343193/220/13343193.jpg[/URL]

[nunoit]

if you look closely at the picture the oscillator is actually 2 components the ceramic cap (105 = 1uf ) and the resistor (?) i marked them better this time.

the blue circle should be KA431

i am concerned with the red circled diode

# 5, i said i thought was the 3.3v output

the items marked in green are caps they come in a variety of shapes. values are usually numbers

can you read the number on the diode behind the heat sink.

yellow brown black = 41 ohms +/- 5% (or high of 43.05 ohm's low of 38.95 ohm's is good) anything else bad you can use the chart provided to help read your resistors easier. you can use windows calculator to get your percentage.

i added some charts for reading resistors and 2 for capacitors. there's also a link to how to read caps here

h**p://www.wescomponents.com/datasheets/capacitor/index.htm

[skywalker999]

Nunoit that diode behind the heat sink it's a HER104 but i have good news power supply is working good now here's what append i previously ad removed that diode to test and it was good at (0.480) then i soldered it back, today when i removed the solder from one leg to get that diode info it fell of the board so i said to my self no could that be causing the power fluctuation so i soldered it back connected the power supply back in the receiver turned power on and tested the output voltage and everything was back to normal my bad sorry for all trouble oh well next time i should be more careful and double check that everything is soldered back correctly

thanks for all the help nunoit and terryl

ps ; nunoit did you ever repaired a stereo amplifier

[nunoit]

good for you. you had what we call a cold solder joint. i guess you learned a lesson in soldering, glad you got it going.

to answer your next question yes i have fixed many boards besides power supply's, radio's, TV's, amps, etc also house hold appliances and auto repairs, in fact i repair many many items.

i would however start a new thread in the section that deals with that topic. just post link to where you started thread.
also i would need pictures of both topside and bottom side of board,
name brand and model number of device help full,
and symptoms of what happened right before it went bad. also what it is doing now, ie. blowing fuses, one channel not working etc.

i would if i were you keep a copy of the charts i posted on my desktop as reference for next project.

[jvvh5897]

Good work nunoit!! Not easy to guide a repair the way you just did!

[skywalker999]

Thanks again nunoit for all the help and i will start a new tread but on the right section do

[Terryl]

A good way to remember the color code is by a little poem.

Bad...................Black=0
Boys..................Brown=1
Ravish................Red=2
Our....................Orange=3
Young................Yellow=4
Girls...................Green=5
But....................Blue=6
Violet.................Violet=7
Gives.................Gray=8
Willingly..............White=9

[nunoit]

Good work nunoit!! Not easy to guide a repair the way you just did!

i try to help the same way you do. coming from you means alot

[nunoit]

Thanks again nunoit for all the help and i will start a new tread but on the right section do

i am glad i could help. it took me many years to learn with out help. just a need to fix cause i could not afford to send out for repair's.


give yourself pat on the back for doing the work. i only suggested where to look.

just post link to where you started the new post so we can follow.

congratulations on your accomplishment.

[Jdread]

I read the entire posts and I can say I also learned a few things from you guys, excellent, the way you were able to bring across the this technical information so simple is amazing.

[nunoit]

maybe skywalker gave up on that amp he was talking of fixing

[skywalker999]

No I did not give up on the amp I was just taking a break nunoit I will be posting on the audio cave section today