Jump to content


  • Posts

  • Joined

  • Last visited

nonionizingemf's Achievements


Member (2/9)



  1. No, the DIN connector is different. Stpeteshepherd does upgrades though and can repair and improve the performance too. He sells repair kits also: https://www.ebay.com/usr/stpeteshepherd?_trksid=p2047675.l2559 The ProMedia 2.1 is like an old PS/2 keyboard or mouse plug with 6 pins and the 4.1/5.1 are different DIN's also that are 8 pins. The 4.1 is the DIN specification is 45326 style: https://en.wikipedia.org/wiki/DIN_connector
  2. I can, though check with: https://www.ebay.com/usr/stpeteshepherd?_trksid=p2047675.l2559 He has the upgrade kits and most likely will do. I had to make a custom cables for two sets... the DIN cable and the speaker cables that needed mono 1/8" barrel plugs. Pretty easy and I can do if you need... though check with stpeteshepard first. Thanks!
  3. Here is a video with a repair that shows not detail other than the components replaced on the newer version ProMedia 2.1 subwoofer.
  4. Did you guys get your systems repaired and working? I have a low volume subwoofer and am suspecting the capacitors around the 1000(1K) ohm resistors above the MOSFET and in the transitor area on the LF board. I tested the MOSFET's and Transistors out of circuit and they seem OK. I tested all the other components on the LF board also other than the capacitors.
  5. Here is the link to the new ProMedia 2.1 schematic: http://www.thompdale.com/bash_amplifier/New_2-1/New_2-1_bash_amp.htm Here is the link to all the ProMedia schematics: http://www.thompdale.com/bash_amplifier/bash_amp.htm
  6. Check the schematic on the site where they are located. There is an new schematic for the newer ProMedia 2.1 boards (no switch or external fuse) as well as the old schematic (switch & external fuse). Maybe that will help for starters. The fuse on the newer board looks like the pink thing (rectangle box through hole component, cartridge I'm guessing is called) from the images. I read somewhere that the new board a MOSFET needed replacing when a fuse is being blown... though not sure if the same situation. I'd check in circuit testable components and traces to see if something is open or out of spec bad. Then you can try testing transistors in circuit unless you notice something strange... which is best to test those like capacitors out of circuit. You can also test the power rails... though be careful when doing so. I'd check continuity first on the plug with a good fuse to make sure there isn't an open circuit like something in the transformer is blown. Same goes on the resistance/continuity of the other side of the transformer. I bought a cheap $7 and now they're $11 LCR meter to test components which works great. You can test the inductors also if bad. I'd go with continuity testing first with a good fuse in, diode testing and then resistance of the resistors. You can also do some testing of the other component with conductivity and resistance testing too... though is more challenging in circuit unless you understand the circuit schematics real well. I'm still not that skilled yet.
  7. Good call on replacing the DIN if that is the issue. I have another set I picked up used from the Goodwill or shopgoodwill.com... I forget exactly. Either way... the DIN plug was broken off where the pins and like Coytee noted the outer silver part of the plug. I wound up cutting off the PS/2 plug from an old keyboard I had lying around since I have a few I picked up free off Craigslist, Offup and/or Letgo. Wired up the re-purposed plug and works great. I'd test the headphone jack on the POD first to see if that is OK or not... if is... I'd suspect the 1/8" barrel plug... if the headphones aren't working in stereo... I'd suspect the DIN plug or connection.
  8. Does anyone have the detailed specs for the upgrade kit? I am about to make an order for a active mini-whip antenna and some other ELF-ULF-VLF projects and figured I can order the components to upgrade the two ProMedia 2.1 subwoofers I am working on repairing, restoring and thinking improving performance if I am critical with components. Looks like the upgrade kit already does the improvement... though I am not able to afford the money for that. I can order all the components from Mouser for eight subwoofers for that price, other than the fan and fan power supply. Mainly I was wondering the specification of the WIMA capacitors. Anyone know the specifications or which item#, part# or model those are? I think the other components I can figure out how to improve performance since the datasheets I've seen show some detail with ST being better than TI or other makes in regards to transistors. The capacitors might benefit in ESR and ripple current for power supply version audio circuit use. Using higher voltage ones might be better also. Higher temperature rated seems like an easy upgrade for improvement. For the resistors, higher wattage rating seems like an easy upgrade for improvement also. I was thinking adding some heat sinks on the inside and a large surface area heat sink on the outside plate most likely mounting with the MOSFET screws... though the fan method does seem easier. Any questions, comments and/or suggestions as well as answers to the questions is appreciated with kind regards. Thanks in advance.
  9. I have two subwoofers that look like the same model. So I have two questions. 1. The subwoofer blows a fuse when powered on. What is the common cause for this? I am noticing ~600ohms from the speaker and that should be 6ohms. I haven't checked anything else as I noticed the sub speaker was installed sideways and the connectors might have already been disconnected when I removed the backplate... I reconnected with a fuse and same deal... little hum and blew the fuse. I happened to only have a 2.5A and 4A fuse also. Looks like they're 2A stock. What is the common cause for this? 2. The second subwoofer wasn't working at all, though not blowing fuses. I found the two 1000(1K)ohm resistors pads completely off the PCB. I resoldered those and found that one satellite speaker would not work. I also found the headphone out was working in stereo... so I concluded must be the barrel plug and not the DIN/(PS/2) connector (I repaired another satellite set with a keyboard PS2 connector that was good since the POD DIN that looked like a PS/2 was broken off at the tips). So, I cut the barrel plug off, tested continuity of each wire which was found good and soldered a new 1/8" barrel plug on and both speakers work now. The only issue is the subwoofer volume is really low. I have the typical burnt area on the PCB around the resistors and MOSFET's on the LF board. I tested the MOSFET's and transistors on the LF board out of circuit and they look OK. I tested the resistors and diodes in circuit and they tested OK. I'm guessing the capacitors around the resistors and MOSFET's are the issue? I don't notice leakage... though all the adhesive is not white and discolored brown with some having bubbles everywhere on the plate. The inductor zip tie is burnt off on both subwoofers, so the system must have been really hot. Any thoughts for quick determination of root cause of low volume? Anyone know what the specs are for the WIMA capacitors used also on the upgrade kits, looks like a 1uF 63V on the LF board and I'm not sure of both and on the PS board? Any reason why not to use Nichicon MUSE capacitors rated at the next higher voltage and higher temp on the LF board if I replace them all other than cost, I was wondering if any part of the circuit needs more ESR at the lower end maybe to filter DC power so not as audio noisy? I was also thinking about cleaning the solder mask off some of the PCB traces and soldering more solder on to dissipate heat and handle the power. Looks like the upgrade kit adds some wire also. Thanks in advance for your time and consideration.
  10. I'm not sure if the same problem... however I found that the headphone was working in stereo from the POD. I also noticed the same one satellite speaker would work and the other would not in a working subwoofer..., since I happened to be testing on a completely dead subwoofer system at first that needed the two 1000W(1K) resistors resolderd to the LF board. Once resoldered... I figured out the two speaker issue and tested on a working subwoofer system. I still have to figure out why the subwoofer volume is really low. I am guessing capacitors on the LF board around the resistors are fried, i.e. dried out or overheated. Back to testing your guys issue.... Therefore, I deduced in my situation, there must be an issue not the DIN... there must be an issue with the 1/8" barrel plug. I took the POD apart and found there wasn't continuity between the middle section of the barrel plug and POD connector. Then I cut the barrel plug to check all the wires continuity and found they were all OK. So, I soldered on a new 1/8" barrel plug and that fixed that issue. Now I'm looking at replacing the capacitors on the LF board since I desoldered and tested the LF board transistors in socket and out of socket with an LCR meter and they along with the resistors and diodes in socket appear to be in working condition.
  • Create New...