I am on my third RF T20001BD. I did find a switch for the first one, and the second one (bought on eBay as parts/not working) actually worked fine. My third is a bit puzzling.
It was rough. Missing front cover, dirty as can be, just rough. It has 4 shorted outputs and all the PS FETs were shorted, as well as their drivers and (open) gate resistors.
I replaced the outputs, removed the PS FETs, replaced the gate resistors, and replaced the drivers. I powered it up using ground and remote, no B+, and went to see if my gate waves looked good... that's when the smoke started.
It popped my new gate drivers. I removed them, and without them in the circuit, I have a great looking gate signal (at the driver).
Drivers Q1/4/15/18 all have gate signal/10v/open on their terminals. IIRC, these are the NPN
The other drivers (PNP) are the ones first to go up in smoke.
I have a diagram, but I'm not sure where I should be looking. I don't see anything obvious (in my eyes anyways) that could be causing this.
I could use some help if anyone can!
It was rough. Missing front cover, dirty as can be, just rough. It has 4 shorted outputs and all the PS FETs were shorted, as well as their drivers and (open) gate resistors.
I replaced the outputs, removed the PS FETs, replaced the gate resistors, and replaced the drivers. I powered it up using ground and remote, no B+, and went to see if my gate waves looked good... that's when the smoke started.
It popped my new gate drivers. I removed them, and without them in the circuit, I have a great looking gate signal (at the driver).
Drivers Q1/4/15/18 all have gate signal/10v/open on their terminals. IIRC, these are the NPN
The other drivers (PNP) are the ones first to go up in smoke.
I have a diagram, but I'm not sure where I should be looking. I don't see anything obvious (in my eyes anyways) that could be causing this.
I could use some help if anyone can!
The PNP drivers are pull-down drivers. If the PS FETs aren't shorted, the zener and 1N4148 that act as a snubber/clamp may be defective.
Replaced all the diodes, same problem. Smokes the mmbta56L within roughly 10 seconds. No PS FETs are in the board. One by one, they pop. Q2, 3, 17, 16.
Bought one of these new, when they were out along with a 100 farad cap.
and the 8004, couple of 12" t1'S wrangler power products alternator and 2 tractor batteries.
That is how you blow a$4K bonus from work, in a matter of hours.
Of course the car stereo shop in that one horsed town was delighted.
Covington, Georgia.
and the 8004, couple of 12" t1'S wrangler power products alternator and 2 tractor batteries.
That is how you blow a$4K bonus from work, in a matter of hours.
Of course the car stereo shop in that one horsed town was delighted.
Covington, Georgia.
With no B+ and no PNP drivers, what's the DC voltage on the emitters of the PNP drivers?
Do you see a square wave on their bases?
Conform that all of their collectors are directly connected to ground.
Do you see a square wave on their bases?
Conform that all of their collectors are directly connected to ground.
9.7v DC on the emitter, 8.9v on the base, no square wave with NPN driver in. I did have waves when there was no drivers in. All grounds connected to collector
I had checked them with my meter and none of them beeped at me. I'll check for waves at the driver IC when I get home. When I replaced the diodes, I also replaced the NPN/PNP (again) so I wouldn't think they should have been shorted.
I'll check the driver IC when I'm home and report back.
I'll check the driver IC when I'm home and report back.
I have square waves at the output of the driver IC. I removed the NPN and now have square waves at the drivers. The NPN base has the square wave, collector has 10V dc, and emitter has nothing.
I don't see what's burning the PNP drivers. Have you used these drivers (both NPN and PNP from this batch) before?
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I have used these before in, I believe, some Pioneer amplifiers.
No DC voltage, no wave form. Maybe I'll install just the NPN drivers, recheck everything, then install the PNPs again.
Maybe I'm overheating them when I solder them in or something? I feel like it's less than a second per terminal.
No DC voltage, no wave form. Maybe I'll install just the NPN drivers, recheck everything, then install the PNPs again.
Maybe I'm overheating them when I solder them in or something? I feel like it's less than a second per terminal.
Figured it out (for now). Put in the NPNs, tested, same thing... 10v everywhere. Thought maybe I mislabeled the drawer so I tested one of the new drivers. Turns out it was a PNP... I'm assuming kids were messing around in my drawers. Had 20 of the 50 strips of PNPs in the NPN drawer...
Going to pull them out and correct the situation, then check again.
Sorry for wasting the time on such a simple deal. Makes sense why 10v was on every leg.
Going to pull them out and correct the situation, then check again.
Sorry for wasting the time on such a simple deal. Makes sense why 10v was on every leg.