Is it a switcher or an AC? A custom transformer is going to be quite expensive. About the only way is to cannibalize another machine. Dwight ________________________________ From: cctalk <cctalk-bounces at classiccmp.org> on behalf of Mattis Lind via cctalk <cctalk at classiccmp.org> Sent: Sunday, September 29, 2019 11:44 PM To: General Discussion: On-Topic and Off-Topic Posts <cctalk at classiccmp.org> Subject: IBM 5110 transformer? A friend of mine is trying to repair a IBM 5110. He is convinced that the transformer is bad. Anyone knows the spec of the transformer? Someone that has a spare? Looking into the tech documentation tell me that the machine requires +/- 5V and +/- 12 V and also +8.5V A very rough guesstimate based on the number of wires from the PSU to the backplane would give 20A 5V, 4A +12V, 4A +8.5V, 1A -5V and 1A -12V. Anyone with a better guess? /Mattis

On 2019-09-30 3:44 a.m., Mattis Lind via cctalk wrote: Does this transformer has a resonant capacitor on it?? They where very common on IBM power supplies from that time period and if the capacitor goes short you will not get any output from the transformer.? This is a lesson I learned as a green service rep 40 years ago after lugging in a very heavy transformer for a machine. Paul.