Hey Guys!
So thanks to this forum, i successfully repaired a Toshiba LCD TV power supply. Component level repairs I've always been pretty bad at, but, simply because I didn't fully understand the process. Now the last repair has me inspired to move on to more and more importantly, learn more.
Anyways. off my soap box. I have sitting here an Onkyo TX SV727 receiver. The second you plug it in, the fuse goes poof and the relay toggles rapidly before eventually giving up. So some voltage does flow through this thing as I do get an amber light. However i get no VFD display or anything else.
I started checking with my meter and found 2 of the output transistors being shorted. ok sweet!
But, i also found, somebody else has been in here. Looks like the output transistors have been replaced at one time, and a pretty rough solder job on the bottom. Even more troubling, something in here looks to have caught fire! Or at the very least, heated up enough to disrupt the traces on the board. Somebody did a solder slob job + jumper wire.
The guy who gave me this claimed it was working and went out one day. I think he blamed lighting, but, i checked the small board coming in and nothing seems shorted there.
I'm sure there's the topic of "Is this worth fixing?" Well, to me, if its a few bucks, some soldering and some learning, yes.
But i come here in case one of you guys looks at this thing and goes "Well theres a good chance the microprocessor is shot" then to me? not worth it.
So here's a few pics of the insides:
Starting from the left, transistor 3 and 4 are shorted. (The smaller ones)
And here's the ugly solder fix job somebody did on the front:
It does seem to tone out ok here though.
So what else should i be looking for when these transistors go south?
Thanks in advance guys!
So thanks to this forum, i successfully repaired a Toshiba LCD TV power supply. Component level repairs I've always been pretty bad at, but, simply because I didn't fully understand the process. Now the last repair has me inspired to move on to more and more importantly, learn more.
Anyways. off my soap box. I have sitting here an Onkyo TX SV727 receiver. The second you plug it in, the fuse goes poof and the relay toggles rapidly before eventually giving up. So some voltage does flow through this thing as I do get an amber light. However i get no VFD display or anything else.
I started checking with my meter and found 2 of the output transistors being shorted. ok sweet!
But, i also found, somebody else has been in here. Looks like the output transistors have been replaced at one time, and a pretty rough solder job on the bottom. Even more troubling, something in here looks to have caught fire! Or at the very least, heated up enough to disrupt the traces on the board. Somebody did a solder slob job + jumper wire.
The guy who gave me this claimed it was working and went out one day. I think he blamed lighting, but, i checked the small board coming in and nothing seems shorted there.
I'm sure there's the topic of "Is this worth fixing?" Well, to me, if its a few bucks, some soldering and some learning, yes.
But i come here in case one of you guys looks at this thing and goes "Well theres a good chance the microprocessor is shot" then to me? not worth it.
So here's a few pics of the insides:
Starting from the left, transistor 3 and 4 are shorted. (The smaller ones)
And here's the ugly solder fix job somebody did on the front:
It does seem to tone out ok here though.
So what else should i be looking for when these transistors go south?
Thanks in advance guys!
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