Retro Tech & Electronics | HVAC Blower Fan Troubleshoot and Repair - Another DIY Repair Saving You Hundreds - @retrotechandelectronics | Uploaded June 2020 | Updated October 2024, 7 hours ago.
It happened again, the AC broke in the middle of the summer. I don't feel like being taken to the cleaner by the AC guy so it looks like i'm going to have to do some old fashioned troubleshooting. That the blower at the compressor was working fine threw me off for a bit, Id quickly realized that the issue was localized to the inside blower fan itself.
After pulling the covers and taping the dummy switch I could hear the hum in the fan that tells me that there is a good chance that the fan capacitor has given up. With all power shut down, the fan is tested for mechanical binding, then the capacitor is removed, and tested on the bench confirming it to be a doorstop.
While waiting for a replacement, the windings are all tested from the fan, including the fuse, all of them have a measurable low resistance, no shorts , no opens. Once the new caps arrives, it is tested on the beck to confirm that it is operating fine before installation.
I prep my unit for diagnostic mode before applying power. checking for codes and operation of the diag procedure. Also cleaning some connectors that need some maintenance. Once the diagnostic cleared, power is shut down to remove the diag setup and reapply power for full operation.
Measurements within the house show good temperature and de humidification. less than ten dollars for a complete AC repair.
#DIY #HVAC #repair
It happened again, the AC broke in the middle of the summer. I don't feel like being taken to the cleaner by the AC guy so it looks like i'm going to have to do some old fashioned troubleshooting. That the blower at the compressor was working fine threw me off for a bit, Id quickly realized that the issue was localized to the inside blower fan itself.
After pulling the covers and taping the dummy switch I could hear the hum in the fan that tells me that there is a good chance that the fan capacitor has given up. With all power shut down, the fan is tested for mechanical binding, then the capacitor is removed, and tested on the bench confirming it to be a doorstop.
While waiting for a replacement, the windings are all tested from the fan, including the fuse, all of them have a measurable low resistance, no shorts , no opens. Once the new caps arrives, it is tested on the beck to confirm that it is operating fine before installation.
I prep my unit for diagnostic mode before applying power. checking for codes and operation of the diag procedure. Also cleaning some connectors that need some maintenance. Once the diagnostic cleared, power is shut down to remove the diag setup and reapply power for full operation.
Measurements within the house show good temperature and de humidification. less than ten dollars for a complete AC repair.
#DIY #HVAC #repair
![Sears Silvertone Twin Twelve 1484 Major Restoration Project [3/6]](https://i.ytimg.com/vi/SAU2KmtoJUQ/hqdefault.jpg "Sears Silvertone Twin Twelve 1484 Major Restoration Project [3/6]
Here in part 3 we continue with preparation with turn-up by installing the pot needed for the hum balance which replaces the filament center tap. After this a dry run without tubes is conducted just to be sure everything is ok. If the tap cant meet 6.3 without tubes it cant be the right tap and i have to switch to the next one. Given the one at around 7 volts its time to add the tubes to the amp.
With all of the tubes in the amp we come to find that the final filament voltage is 5.9. It looks like another turn or two will be needed out of that transformer. A retest with 2.5 wraps shows 6.2 volts at 120vac.
Following this The temperature gun will be used to measure the heat off of the transformer after 30 minutes or so. No heat issues were found. To celebrate, the transformer covers were stripped and painted, as well as the rewiring of the reverb tank.
I break out the impedance bridge to test the cabinet and confirm the impedance at 8 ohms.
I found an extra speaker jack that was inappropriately added to this cabinet that I could remove to place the hum pot into. After that, its time for the first full smoke test.
I wish this amp had an adjustable bias..... also I discover at this time that the standby circuit is garbage. I end up having to use several tubes from Cornerstone music to find something that operates within safe parameters.
This brings the project into the noise isolation phase. and there is no shortage of noise in this amp; all sorts of different types of noise from different stages.
This starts from the finals backwards to the phase inverters. Where things are already looking strange.
#retrotechandelectronics #vintagetubeamprepairs")
