WFCO 3-stage Converter problem

[Armin]

My travel trailer's WFCO 3-stage Converter (model 7155) seems to be acting up. 12V trailer lights are very dim, propane alarm is beeping, etc.
I pulled it out, put it on my workbench to test it. When I supply 120 VAC on the input I get a measurement of 7 VDC on the output. Does this mean it's defective? Is there anything I can check/adjust on it or do I need to spent $500+ to buy a replacement?
Thanks for any ideas.

 

[John From Detroit]

Short answer YES
Now I'm told there is a very easily replaced part (A resistor) that likes to go POOF on those but.....

Is this an intergrated (Fuses, breakers and electrons in one major assembly)
or a stand alone (Fuses and breakers elsewhere)

FIrst Progressive Dynamics 4600 series
Second 9200 series

Try to match the last two digits of the model number.

 

[Lou Schneider]

If the converter is built into the power center (i.e. not a standalone unit) Parallax has an excellent drop-in replacement unit for a lot less than $500.

https://www.amazon.com/Parallax-Power-Supply-081-7155-000-Replacement/dp/B002SSEWD8

A common failure is the two large black filter capacitors.  They should have flat tops and sides, if they're bulging upward or outward they've failed.

https://www.youtube.com/watch?v=3jyfZ4tqx6I

If you take them out, be sure to note their polarity.  The new ones have to go in the same way.  Replacements can be obtained from an electronics supply store or on Ebay.

 

[Gary RV_Wizard]

Are you sure it's a WFCO? The 7155 model is usually associated with Parallax Power, not WFCO. The similar WFCO would be the 8955.  If it's a Parallax  7155 or WFCO 8955, you can replace the innards (the converter/charger) for around $200. Here is one source:

http://www.bestconverter.com/7155-Lower-Replacement-Section_p_232.html
or another:  https://www.amazon.com/Parallax-Power-Supply-081-7155-000-Replacement/dp/B002SSEWD8

 

[Armin]

Thanks for the tips everyone!
The front panel says WFCO but the circuit board says 7100/7155.
Looks like I'll order the replacement that Gary suggested from Amazon. It looks identical to the one that failed.
Thanks!