Older Metcal cable repair/replace - Page 1
Forum section: electronics / repair

author: DaveDC
author_rank: Newbie
timestamp: July 16, 2025, 02:58:05 am
content: I have an old-school Metcal model STSS-001 Soldering System with the RFG-30 Power Unit (SN 400xxxx). Everything works fine, but I'm noticing that the hand piece cable is getting hot right where it joins the wand. I suspect that it has a dodgy connection in there that is self-heating. Does anyone know if the later model hand pieces (for the MX series, etc.) are compatible with this older unit? I'm quite sure that the tips are compatible (unlike the SP200 series, whose tips are not compatible), so I'm hoping that I can just buy a replacement hand piece. Or does anyone have any advice on how I might repair the cable? Thanks in advance for any info!

author: Runco990
author_rank: Frequent Contributor
timestamp: July 16, 2025, 09:03:02 pm
content: It's the same as the MX-500 and up series like the Thermaltronix and OKI.The cable is just a coax. The braid begins to fray and break right at the handpiece. I have fixed many of them. Once you crack the glue holding the hand piece together, it all comes apart and you can shorten the coax by an inch and solder it back on the socket the tips seat in.Or you can make a new coax as well. I actually am lucky enough to have an internal Metcal "Hand piece tester". You plug both ends into it and it can determine if the coax integrity is still good or not. It's a go/no go test. It uses RF to test, NOT continuity.It's really not difficult to repair, before I'd EVER spend $100 plus for another hand piece.

author: DaveDC
author_rank: Newbie
timestamp: July 17, 2025, 09:26:53 pm
content: Wonderful. Thank you for the advice!

author: DaveDC
author_rank: Newbie
timestamp: July 17, 2025, 09:39:02 pm
content: @Runco990: Could you please describe exactly where the handpiece is glued? Is it the joint between the plastic body and the rubber cable strain relief? Mine is very firmly secured and doesn't look like it will come apart without being totally destroyed. Thanks!

author: scrofula
author_rank: Contributor
timestamp: July 26, 2025, 07:47:15 pm
content: Hi, let me help you, tell me what kind of pen you have, old or new? MX-RM3E or new MX-H1-AV

author: BurningTantalum
author_rank: Frequent Contributor
timestamp: July 27, 2025, 08:27:44 am
content: The RM3E wand has a resistor fitted that tells the MX500 that the wand is connected/OK. The RM2 wand does not have this resistor so will work with the RFG-30 unit but not with the MX500 unit.There is some info on repairing the cable relevant to both wands here (it may help with your handle):https://www.eevblog.com/forum/repair/metcal-mx500/msg2316792/#msg2316792

author: DaveDC
author_rank: Newbie
timestamp: July 29, 2025, 03:59:41 pm
content: Hi scrofula: I have the MX-RM3E. The model number is printed on the connector that connects to the control unit.

author: thm_w
author_rank: Super Contributor
timestamp: July 30, 2025, 01:02:18 am
content: Quote from: Runco990 on July 16, 2025, 09:03:02 pmI agree its worth repairing, but its also worth upgrading to the MX-H1-AV if budget is available ($180). Grip is much nicer.Newer handle will work with the RFG-30, but, you might need a $2 F connector R/A adapter, as even though its the same connector there is some variation in the pin sizing, etc.