I am looking for help identifying a burnt out resistor or diode on my heart interface HF12-1200SX inverter/charger. Or perhaps someone has a circuit diagram??

I would almost guarantee that more than two resistors are the cause. Be sure to check all components around the resistors an check all transistors. Since you have it open check caps an diodes as well. Look on the board it may tell you what values are.

Hello, I was able to fix this charger via replacing several parts in the source part which were either short-circuited (transistors and diodes) or burnt (resistors):
F1 (fuse 2,5A)
R5 0,91R +-1%
V5 (ST)P6NK90Z
V1-V4 1N4007
V6 2N3904
V8 1N4148
R7, R8 300k +-2%
This won't help after 5 years, but maybe it can be helpful for someone else.

Did you try contacting the manufacturer? The resistors are color coded and no problem to replace but the zener diode is another matter. Take it down to a repair shop and perhaps they can identify it from the markings and/or size.

How are you measuring the output? The inverter makes alternating current and it can be measured wrong. Also it might be high if a regulator is bad and also if there is no load on the output..

hi im alwin the Q45 is JE200 while the Q47 is JE210,goodluck,

try the local repair section of fixya

The zener diodes are 1N4774, I believe they are one watt. Try 3 watt metal oxide for the resistors. You might as well replace the 6800uF 63 volt main filter capacitors and the 220uF 50 volt capacitors while you're at it. Half the time the heat that cooked your other parts takes them out as well.

the charge fuse may have broken or the charger is bad

I have the same exact problem in a 12 volt Lincoln battery charger. Burned resistor in R5.

http://www.centurytool.net/SE_1275A_Schumacher_Battery_Charger_Parts_List_s/30818.htm