stpete cooling

This is the component side of the 2020-current replacement available for the ceramic BASH HC1011 (as well as the rarer HC1010 and HC1012) boards.

I realize this is a very old thread, but since mid 2020 there is a non-ceramic replacement option for the troublesome ceramic BASH HC1011 boards. I've had great results with hundreds of the new boards (most people find them on ebay). An engineer in Washington helped me produce a non-ceramic replacement that avoids the intermittent connections that develop on the brittle ceramic boards after thousands of heat cycles. Ceramic would have originally been chosen to handle high temperatures, but in the ProMedia 4.1 and 5.1, the ceramic boards do not actually get hot enough to need ceramic. Ironically, a daughter board in the 5.1 actually does get hot enough to char, but that was not made using ceramic boards. (That daughterboard problem is alleviated with another new board the engineer also helped me develop, plus the mounting of a silent fan to move air in the tight confines of that board's location).

The static is not from the line filter board. Static typically is from noise generated on the AC-DC converter board. To remove the line filter board, though, you need to desolder all four pins. The only times that board is removed is if the thermal fuse for the transformer blows, or to replace the metal oxide varistor (MOV). The relay can be replaced without removing this board.

That is a 100,000 ohm resistor. It is likely fine. I've replaced over 1,000 of these, as part of every repair I do. I upgrade them to 2 watt, but I recall well under .5% of panels actually having that resistor fail. More often the 205,000 ohm resistor (1/8 watt) by the transistor on that board will rise in value and fail, or there will be charring between the two 470 ohm resistors at the bottom of that daughter board. That charring eventually burns out a nearby IRF740 MOSFET (power transistor) and a 22 ohm and/or a 390 ohm resistor on the daughter board. It has been years since I logged in to this forum. Glad my notes from years ago still are helpful.

The fact that the hum does not go away when the cables are unplugged serves to verify that the problem is not in the signal source (e.g., sound card) nor input cables. The capacitors nearly always take care of the hum issue. Once I've installed 105 deg. Celsius rated capacitors, I have not had that hum return. It may help that my panels also have a fan moving air inside the sub enclosure, evening out the temperature and removing heat more quickly from the two heat sinks near those capacitors. 100 mFd refers to microFarads, same as uF, just as mmfd used to be micro-microfarads, and now is referred to as picofarads. (the F was sometimes capitalized in honor of Faraday, for whom the Farad unit was named). Once the weak spots have been addressed, I've seen these systems perform well for years.

There is a 4.7 ohm resistor on the panel that sometimes overheats and burns out. It is in series for a power supply circuit. If it fails, though, there could be another problem causing that failure in the power supply (such as an IC preamplifier on the panel). There is a demand for 4.1 controls on eBay, if you end up parting out your system. I think it can be repaired, though.

Sorry to hear of these frustrating experiences. If you do decide to get rid of your system, I would be interested in buying it in non-working condition. I've repaired hundreds of these, and have had great results. I believe cooling the ProMedia 5.1 amplifier's power supply (AC-DC converter) is key, and have seen the stark difference between ProMedia 5.1 circuits that had been cooled for the past few years, and those that had no airflow with sections sitting at 180+ degrees F (think "well-done steak"). It is not in the spirit of this forum to advertise here, (and I'm plenty busy already doing repairs--keeping my turn around time to 1 week is important to me), so I am just noting if you no longer want your panel or entire system, I'd offer to buy it (salvage and improve it), than rather than let it be trashed/destroyed.

Sorry, I only checked the forum a few times a year, and just spotted your post. The problem you describe is frequently from one of three causes: a 2N5551 transistor (more likely on the older THX panels, but at 8 years, your Ultra is getting in range for this transistor to fail), a 22 volt zener diode near it, or the BASH HC1011 chip for the satellite section. I've seen this problem many times. The first two components sit on a board that gets quite hot, and I've seen the diode, transistor and some capacitors fail from that heat. That's one reason why moving air past that board to bring the temperatures down has been effective (eliminating charring, arcing and shorting at the other end of that AC-DC converter is the other reason to install a fan for airflow). The panel should be repairable.

If the system does not hum when the input cables are removed from the back of the panel, it is likely that one of two 35v 100mFd capacitors on the main board have dried out. Whenever I repair these panels now, I always upgrade those two capacitors to 105 deg. Celsius rated versions (even on boards that are not yet humming). I believe one of two other places doing repairs is now doing the same. Much rarer is that one of the nearby 16v 100mFd capacitors has dried out. All four sit next to a heat sink that is always quite warm.

The hum is almost certainly from one of two 100mFd 35 volt capacitors on the main board next to a pair of small, black heat sinks. You have to be careful removing the old capacitor that you don't damage the leads--they are a bit difficult to access with a soldering pencil. I always replace these as part of every repair--the hum is so common on older panels. I recommend using 105 degree Celsius capacitors, in place of the original 85 degree rating. I also bend into a "Z" (offset) the lead that will be closer to the heat sink so that the capacitor is mounted as far from the heat sink as possible. The control boxes on eBay vary widely in price. One sold for $82 plus shipping this week; another sold for $24 something and shipping.

Sorry I did not check back sooner, and was not clearer. If someone had started troubleshooting further and had new questions as they went, I was offering to help from my experience. I have repaired panels for others, but I am not sure Klipsch or forum readers want either a private person (e.g., me) or a business to be seen as soliciting. If you wish to contact me via email or private message, that may be the best method for repair options outside the forum.

I could tell someone had worked on it because there is a small yellow piece of insulation (not original) at the bottom of the board. That is an area where the heat is the worst, and arcing eventually develops. Perhaps someone previously repaired that section.The daughterboard does need to be removed in order to replace more than the top part or two. A desoldering gun (like Hakko's 808?) or heating all pins simultaneously with a bar of solder-soaked braided wire can accomplish the removal. Based on that board's color, I'd replace all but the the HT-60 diac, the transistor, the 1.00 k 1% resistor and the two 1N3070 diodes (replacing the other 15 parts). Be careful with that board, the traces are very thin and easily damaged. When reinserting the board, be sure all 8 pins are back in circuit. If I can help, let me know.

The problem is not with that section. Your photo shows the standard, correct connections. However, the photo does show that someone worked on the daughterboard next to those circles, and that board is prone to fail from heat. It was originally bright green. You could have a main relay problem, but as part of any repair I would go through and replace and upgrade the wattage of the 470 ohm (2, to 1 watt), plus the following 1% precision resistors: 205,000 ohm, 392 ohm (2) and 22 ohm (2) (to 1/4 watt). The precision resistors are prone to fail or change values, causing problems. Without seeing the panel, though, there is no way to be certain what the cause is.

I've seen hissing happen from capacitors drying on the power supply, or one of the BASH chips failing, or arcing on the power supply's daughterboard due to charring from longterm operation at high temperatures. Humidity will make a difference on the arcing (making it intermittent with the humidity in the room). Those are the most common I've found. There could be a few other causes. Of those causes mentioned above, I've generally been able to repair them, and get rid of the drying and charring problems. There really are few options that give the nice sound and power of the ProMedia 5.1. If I can be of further help, let me know.

Sorry to hear of your problem. The 5.1 speakers are designed for up to 60 watts rms (though I'd feel more comfortable limiting them to 40 watts rms, like on the RSX-3s, which are heavier). I've found Harman Kardon makes some nice receivers, more accurately rated than other common brands when they list their output power. You will have difficulty, though, finding a receiver that includes a subwoofer amplifier. The ProMedia 5.1 subwoofer has a higher impedance than is typical for subwoofers, which will not hurt an amplifier, but means an amplifier rated at 4 ohms will need to have a higher wattage to drive a higher impedance like the ProMedia 5.1's. (Sub amp in the Ultra has a 170 watt rating (each driver was rated for 100 watts). Something like a Sub-10 subwoofer would work to replace your sub, set for frequencies up to 116 Hz. I've had good success with the ProMedia amplifiers once I've upgraded some weak components and added cooling. (I've made hundreds of internal cooling kits since October 2005). At some point all electronics will die, of course, but it seems that once the internal hot spots are eliminated, the system's reliability falls in line with other electronics. It will also be hard to beat the compact size of the ProMedia 5.1 amplifier package when you try to locate a beefy receiver like an HK. I have not found a plate amplifier that exactly matches the ProMedia 5.1 sub's plate dimensions.