Morning All,
The units red LED lights up, but no sound at all.
I have tested all components, except for the relays, the zener diodes, and the ICs' (I do have a list of measurements but don't understand them). If a component did not test correctly in circuit, I have removed, tested, and refitted, and so far all test O.K..
The unit was not fitted with the Green Auto-LED (there is no mount / hole), which I have subsequently fitted (the PCB has the required header). This had no effect and does not light.
I get +15v & -15v at Con105 shown centre of the schematic which connects both PCBs'.
I get +44.8v on the collectors of Q107/8 & -44.8 at Q110/111 output transistors (?).
I have a reasonable DMM, but no 'scope.
Cheers & hope someone can help,
Tony
The units red LED lights up, but no sound at all.
I have tested all components, except for the relays, the zener diodes, and the ICs' (I do have a list of measurements but don't understand them). If a component did not test correctly in circuit, I have removed, tested, and refitted, and so far all test O.K..
The unit was not fitted with the Green Auto-LED (there is no mount / hole), which I have subsequently fitted (the PCB has the required header). This had no effect and does not light.
I get +15v & -15v at Con105 shown centre of the schematic which connects both PCBs'.
I get +44.8v on the collectors of Q107/8 & -44.8 at Q110/111 output transistors (?).
I have a reasonable DMM, but no 'scope.
Cheers & hope someone can help,
Tony
Attachments
Last edited:
The 4 main Q107/8 & Q110/111 show 63mV to 66mV all in the +ve range, no -ve.
This quite sometime later, from an email request;
"My memory does not go back that far, but I do vaguely remember replacing the blue Goodsky relay. I have found my hard-copy notes & I did purchase a relay from RS Components, part # 366338. The invoice description; DPDT PCB power relay,5A 24Vdc. I've also handwritten "G2R-" on the invoice. I have a bunch of A3 & A4 pics with LOTS of annotations if this also helps.
"My memory does not go back that far, but I do vaguely remember replacing the blue Goodsky relay. I have found my hard-copy notes & I did purchase a relay from RS Components, part # 366338. The invoice description; DPDT PCB power relay,5A 24Vdc. I've also handwritten "G2R-" on the invoice. I have a bunch of A3 & A4 pics with LOTS of annotations if this also helps.
Haha, good memory!
I pulled both relays off my board just now, and the bigger one tests ok, but the smaller (RL100) one shows blown coil. $2.85 from AliExpress Relay JT32F 024 HS 4PIN A group of normally open 5A250VAC JZC 32F 024 H-in Relays from Home Improvement on Aliexpress.com | Alibaba Group haha
For ref, my RL101 is a Tianbo "TRA3 L-24VDC-S-2Z" https://produktinfo.conrad.com/date...-01-en-RELAIS_24V_DC_2NO_TRA3L_24VDC_S_2H.pdf
And smaller RL100 is a "JZC-32F 024-HS" Cirrus Logic - datasheet pdf
I pulled both relays off my board just now, and the bigger one tests ok, but the smaller (RL100) one shows blown coil. $2.85 from AliExpress Relay JT32F 024 HS 4PIN A group of normally open 5A250VAC JZC 32F 024 H-in Relays from Home Improvement on Aliexpress.com | Alibaba Group haha
For ref, my RL101 is a Tianbo "TRA3 L-24VDC-S-2Z" https://produktinfo.conrad.com/date...-01-en-RELAIS_24V_DC_2NO_TRA3L_24VDC_S_2H.pdf
And smaller RL100 is a "JZC-32F 024-HS" Cirrus Logic - datasheet pdf
Its hard to read that schematic, the resolution isn't quite enough, but I think that's the output relay which would the lack of output.
Not convinced by the choice of subminiature relay with very large coil resistance in a high vibration environment. Very fine wire in a 24V coil, even worse in the "sensitive" option.
A better relay might be wise, but the relay driver components may need upgrading.
Not convinced by the choice of subminiature relay with very large coil resistance in a high vibration environment. Very fine wire in a 24V coil, even worse in the "sensitive" option.
A better relay might be wise, but the relay driver components may need upgrading.
Yeah, hoping it's just natural wear and tear, rather than blowing because something else is faulty on my amp.
Anyway, new part on order. Seems like thats a pretty common form factor for SPST-NO relay. Available also on Digikey: OJE-SS-124DM,000 TE Connectivity Potter & Brumfield Relays | Relays | DigiKey Probably better than the aliexpress one.
Anyway, new part on order. Seems like thats a pretty common form factor for SPST-NO relay. Available also on Digikey: OJE-SS-124DM,000 TE Connectivity Potter & Brumfield Relays | Relays | DigiKey Probably better than the aliexpress one.
I just bagged one of these and it appears the Plate Amp is distorting. Driver seems fine.
Any ideas on what this could be?
I have an OK budget Meter and rudimentary laptop DIY scope that can show waveforms but cant seem to do voltages.
Any ideas on what this could be?
I have an OK budget Meter and rudimentary laptop DIY scope that can show waveforms but cant seem to do voltages.
Similar symptoms - mine's now fixed
Old thread, I'm jumping on but my SW150 stopped working last night. It was dead when I turned it on, just the red power LED, no output.
Armed with the schematic from the manual linked above I found the PSU was not working.
AC meter measuring across the Anodes of D105 and D107 showed virtually zero, yet across the two fuses was approx. 70 V ac.
Disconnected and got the meter leads in to check continuity of the NC contacts of the RL101, both were OC.
Removed transformer bolt to get to the relay and remove it. Quick replacement and back up and running.
Happy days 🙂
Old thread, I'm jumping on but my SW150 stopped working last night. It was dead when I turned it on, just the red power LED, no output.
Armed with the schematic from the manual linked above I found the PSU was not working.
AC meter measuring across the Anodes of D105 and D107 showed virtually zero, yet across the two fuses was approx. 70 V ac.
Disconnected and got the meter leads in to check continuity of the NC contacts of the RL101, both were OC.
Removed transformer bolt to get to the relay and remove it. Quick replacement and back up and running.
Happy days 🙂