Rockford 55.2 PC-1882-A
Power was hooked up backwards. Blew the power supply and D2 and D3.
Repaired power supply. With D2 and D3 replaced and in circuit makes a direct short. With these removed the amp powers up and works fine.
I can't find anything wrong?
Power was hooked up backwards. Blew the power supply and D2 and D3.
Repaired power supply. With D2 and D3 replaced and in circuit makes a direct short. With these removed the amp powers up and works fine.
I can't find anything wrong?
I know you're experienced so at the risk of asking dumb questions:
Are the anodes connected to the B+ tap of the torrid?
Are you using the correct 39v zeners?
Is the short across the Battery and Ground without remote applied?
Do you have a schematic? I think the 100x2 is close enough.
Are the anodes connected to the B+ tap of the torrid?
Are you using the correct 39v zeners?
Is the short across the Battery and Ground without remote applied?
Do you have a schematic? I think the 100x2 is close enough.
The original parts are 1N5336B that's what I replaced them with.
The short happens when battery and ground are hooked up with no remote.
I don't have a schematic for this one.
The anodes are not connected to the positive tap, but to ground.
With these removed the amp works flawlessly, I've had this happen a few times years ago and never found a fix. One of the amps I repaired is still in use after 12 years with these parts removed.
The short happens when battery and ground are hooked up with no remote.
I don't have a schematic for this one.
The anodes are not connected to the positive tap, but to ground.
With these removed the amp works flawlessly, I've had this happen a few times years ago and never found a fix. One of the amps I repaired is still in use after 12 years with these parts removed.
The 100x2 is completely different than this amp looking at the schematic, maybe I'll have Rockford send it to me.
I will have the schematic in the morning.
Are these used for reverse polarity protection? If so they didn't work the 1st time and probably won't again lol. I might just leave them out.
Are these used for reverse polarity protection? If so they didn't work the 1st time and probably won't again lol. I might just leave them out.
I in no way meant to suggest the entire amplifier will be similar. Just the area of interest. I pulled up several other schematics that use this diode and they are all Anode to center tap. If you're following silkscreen, perhaps it's a screen error? That does happen from time to time.
They wouldn't use a pair of 39v zeners for reverse polarity protection.
They wouldn't use a pair of 39v zeners for reverse polarity protection.
The diodes are used to clamp spikes/ringing. They are connected across the intrinsic diodes in the PS FETs. They may read as connected to the primary CT but they're actually connected to the ends of the windings.
I don't bother to reinstall these. The intrinsic diodes can clamp any spikes and are on the heatsink so they can survive the heat better.
In the newer amps (for the last 25 years?), they use the 33v Zener and the FETs to clamp any spikes.
I don't bother to reinstall these. The intrinsic diodes can clamp any spikes and are on the heatsink so they can survive the heat better.
In the newer amps (for the last 25 years?), they use the 33v Zener and the FETs to clamp any spikes.
The amp has been playing on the bench since my first post and works flawlessly.
Why would these cause a direct short between power and ground when installed?
They were in as factory parts and didn't short then?
I'm not going to put them in but was just wondering why this is happening?
Why would these cause a direct short between power and ground when installed?
They were in as factory parts and didn't short then?
I'm not going to put them in but was just wondering why this is happening?
They do before going into circuit then if I try to apply B+ and ground the amp shorts.
In circuit after a power connection attempt they read 0.000v either direction.
This is frustrating because I can't determine what is causing this?
As soon as they are installed into the amplifier no power connection attempt, it makes a direct short between B+ and ground using my meter to test.
In circuit after a power connection attempt they read 0.000v either direction.
This is frustrating because I can't determine what is causing this?
As soon as they are installed into the amplifier no power connection attempt, it makes a direct short between B+ and ground using my meter to test.
Have you used diodes from this batch in other amps?
If you ground the anode and connect the cathode (striped end) to the B+ of your power supply (through a limiter), does the diode pass any current?
I realize that they're appearing to fail with no power applied. The test above is just a test.
If there is no current draw in the test. Heat the diode as it would be when installed. Does it short?
If you ground the anode and connect the cathode (striped end) to the B+ of your power supply (through a limiter), does the diode pass any current?
I realize that they're appearing to fail with no power applied. The test above is just a test.
If there is no current draw in the test. Heat the diode as it would be when installed. Does it short?
I have only used out of this batch twice. I rarely see these fail.
I have attached the schematic.
I will try that test Perry and let you know.
I have attached the schematic.
I will try that test Perry and let you know.
That's not the right diagram. That's an SMD amp.
Clarification. 1N5336 or 1N5366?
5W 39v zener?
Photo of the board?
Clarification. 1N5336 or 1N5366?
5W 39v zener?
Photo of the board?
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Did you mean DSM amp?
I didn't catch that the board number was different. They may be the same amp, I'll ask for another schematic.
1N5336 is what I'm using. This is all I've ever seen in Rockford amps that have these in them. I think the HD's even had them.
I'll post a photo as soon as I can.
I didn't catch that the board number was different. They may be the same amp, I'll ask for another schematic.
1N5336 is what I'm using. This is all I've ever seen in Rockford amps that have these in them. I think the HD's even had them.
I'll post a photo as soon as I can.
I don't ever remember seeing those diodes in an amp that used SMD parts. The diodes are almost certainly 1N5366 Zeners. The 1N5336 would short/conduct immediately when B+ was applied. I can't explain them shorting with no power being applied.