1999 Hyundai 210 LC-3 monitor/cluster issues.

I recently bought a 99 hyundai 210 lc-3 which operates decently but the mode selection was kind of funky. I could only select H or F( supposed to default on S) .Initial testing revealed the cluster was faulty. The rest of the monitor functions and display works OK. So i decided to purchase a new monitor from China cause they are half price of dealer price. When i plugged the new cluster in it did nothing, it would not light up at all. When i contacted the seller he advised me to send it back for testing and they would send another one which they did,..It too did not work on my machine when i plugged it in,. yet when i plug in my old one it worked right away except for the mode selection part. the part # on my original monitor is 21E6 00200. the part # on the new one is 21E6 00201 AS which according to Hyundai is a direct replacement for my machine yet i got two in a row that don't work. The seller just informed me that the monitor i send back was tested by Hyundai heavy industries in Korea and was found fully operational and they advised me that there must be a glitch in the power supply, grounds or other electrical down stream yet they failed to explain why my original monitor still works flawlessly when plugged in and theirs does nothing. I decided to check the connectors and the wiring for continuity and found all but one connector terminal OK. the one terminal that did not seem to contact the pin i managed to adjust back to proper pin tension and contact. When i plugged my original monitor back in the mode selection defaulted to S as it is supposed to and i can select all 4 of them with the buttons. so i guess i fixed da problem When i plug in the new monitor it again remains dead as a door nail. The dealers i talked to say the cluster part % 21E6 00201 is indeed the correct replacement for my machine Can somebody shed some light on this mystery cause i am completely stumped. My machines ser # is EM01CL10451 Thanks