Ground Zero 1.10000 power suply !!

[apolodor]

Hello for all members..I have a ground zero 1.10k and i have power suply broke.Amplifer had a output transistor broken and driver board broken.i change all output transistor/gate resistance/ audio driver/tl494 and driver transistor for suply.The transistor drivers from supply i changed with bd140/bd 139.When loading the power suply(12v) the output raley coupling and the red led light stay ON but very dime.
Imeasured voltage on ic tl494.
1-0
2-4,9
3-0
4-4,31
5-1.58
6-3,59
7-0
8-12
9-0
10-0
11-12
12-12
13-5
14-5
15-5
16-0.65
I don t understand why no have output signal from tl494..

 

[Perry Babin]

It's best to use something other than a hyphen as a separator. It could be taken as a negative sign in some instances.

Pin 4 is being driven high. It needs to be near 0v.

Post a photo of the board in the amp.

 

[apolodor]

This is the photo with tl494. You want a photo with all motherboard?

 

[apolodor]

Photo with rear pcb

 

[Perry Babin]

Pin 4 appears to be driven by the transistor near it. Removing that transistor and grounding pin 4 should allow the amp to power up but the protection circuit will be disabled so you will have to take all normal precautions when a protection circuit is disabled.

 

[apolodor]

but this transistor drive the protection.??

 

[Perry Babin]

I don't understand the question. It's likely that this transistor shuts the power supply down when there is a problem with the output stage. Removing it allows the amp to power up so that you can determine what the problem is with the output stage. It's somewhat risky but often the easiest way to troubleshoot a problem. Don't do it if you're not experienced enough to deal with possible the risks.

 

[Perry Babin]

Post a photo of the entire main board and another photo of the audio driver board.

 

[rrae]

Yes, Ground zero had many versions of 10k amps.

 

[apolodor]

tomorow morning i will upload a few photo HD.i know the risk without protection ..when i work without protection i make step by step and put a multimeter on the celsius degree on the transistor to see temperature.

 

[apolodor]

hello boys..this is the amplifier.

 

[Perry Babin]

Did you try removing Q42?

 

[apolodor]

i remove the transistor...whe connect power suply :
-The led is green
-I have around +0-50v(power suply is from transformer 12 v ~5A)
-3 pcs output transistor heat up.
I think the problem is from driver board because before i changed audio driver(4pcs)irf(smd)..because before was burned all audio driver and all output transistor, and me i changed only the audio driver and output transistor
i remove the audio driver board for make a photo?
i m sorry for my bad english.if you don t understand something ,ask me.thank you for all

 

[apolodor]

i forgot ...i have 30khz pwm after driver transistor bd139/140

 

[Perry Babin]

"-I have around +0-50v"

Please clarify this statement.

 

[apolodor]

- vs gnd i have 50v
+ vs gnd i have 50v
-vs + i have 100v
the power supply work good..

 

[apolodor]

i removed the transistor wich heat up..
i connect power suply 12 v
led is green,relays couples but in output i have DC power...
what must to check....i think the problems is from audio driver.

 

[rrae]

I would recommend when troubleshooting output driver card, install "socket" on the main board, so you can pull it off many times as you want, so you don't need to desolder it from the board.

Which transistor you removed? Amp doesn't go in protection with DC on the outputs?
You mentioned, that you have failed output transistors, you rebuilded output driver card? If so, what did you replace?
When outputs fets fail, you MUST have to replace their drivers IRS21844 and check carefully all driver card.

I would also suggest to buy Perry full tutorial, there are a lot of useful information!

 

[apolodor]

i removed the driver card and is big problem..all driver irs21844s is broken,all rectifiers smd is broken and 2 transistor ....but i don t know the name of transistor q2 and q10....i will buy all components ,tl072.4xirs21844s,lm293.x6n(rectifier) andQ2,Q10...Somebody know q2 and q10..thaks!!!!

 

[Perry Babin]

Transistor marked MAX - KTD1304