I asked AI, it helped me ID the legs and gave me some values to look for, so i can find oit if that piece of wire came from the transformer or something else.
Here is the answer I got from GROK BTW, incase anyone want to point out any incorrect information or finds it useful...
EDIT: THE FOLLOWING INFORMATION IN HAS PROVEN TO BE INCORRECT!
The T101 transformer in the Wells Gardner U5000 arcade monitor chassis (part number 053X0631-001) is the switch-mode power supply (SMPS) transformer located on the power supply board. It handles the conversion from the AC input (90-264 VAC) to the various DC rails needed for monitor operation, including the B+ rail (typically ~155 VDC at test point 203).
Pinout and Secondary Legs
The T101 transformer typically has 10 pins (5 on each side of the bobbin), with the primary winding(s) on one side and multiple secondary windings on the other. Based on standard SMPS designs for this chassis and similar Wells Gardner models (e.g., U2000), the pinout is as follows (pins numbered from left to right, bottom to top on the secondary side; confirm with your board's silkscreen or schematic for exact orientation):
Primary side (high-voltage input, typically pins 1-5): Connected to the switching MOSFET (Q101, SSP6N60A or equivalent), PWM controller (U101), and input filter. This side operates at high voltage (~140-340 V rectified DC) and 120 kHz switching frequency. Do not probe live without isolation.
Pin 1: Primary winding start (connected to drain of Q101).
Pin 2: Primary winding end (connected to input DC bus via snubber/filter).
Pins 3-5: Auxiliary primary winding for feedback and startup (connected to optocoupler feedback via U101 and resistors like R104, R100).
Secondary side (low-voltage output, typically pins 6-10): These are the "legs" for the secondary windings, providing isolated low-voltage outputs for control circuits, deflection, and other rails (e.g., +12 VDC, +5 VDC, and auxiliary ~18 V for horizontal drive). The secondary is grounded separately from the primary for isolation.
Pin 6: Secondary winding 1 start (common/ground for main secondary, often tied to chassis ground via diodes like D104-D107).
Pin 7: Secondary winding 1 end (provides ~18-24 VDC rectified for B+ startup and horizontal deflection via D107 and C107).
Pin 8: Secondary winding 2 start (auxiliary secondary for +12 V rail, rectified via D106).
Pin 9: Secondary winding 2 center tap or end (tied to ground or filter for +12 V).
Pin 10: Secondary winding 3 end or feedback auxiliary (provides ~5-12 V for PWM feedback and low-voltage rails, often rectified via D105 for TP103/TP104 test points).
The secondary legs (pins 6-10) are the low-voltage outputs post-isolation. Connections include:
Rectifier diodes (D104, D105, D106, D107) and capacitors (C104-C107) on the secondary side to generate DC rails.
Output from pin 7 (via D107) feeds the B+ filter and regulation circuit (R760, R765, etc.).
If a wire has fallen off T101 (common issue reported in repair forums), it's likely from the secondary side (e.g., pin 7 or 9), causing no-start or low-voltage symptoms. Visually inspect for melted insulation or loose solder on these pins.
To test:
Disconnect power and discharge caps.
Measure DC resistance (DCR) across secondary legs (e.g., pins 6-7 should be low ohms, ~0.5-2 Ω; pins 8-9 ~0.2-1 Ω). High or open DCR indicates a failed winding.
Primary DCR (pins 1-2) is higher (~10-50 Ω). Use a ring tester or LCR meter for inductance (primary ~1-5 mH at 120 kHz).
Impedance of T101 Transformer
Transformers like T101 do not have a single "impedance" value; impedance is load-dependent and frequency-specific (rated for 120 kHz operation in this SMPS). Instead, key specs from the service manual and repair data are:
Turns ratio: Approximately 20:1 (primary to main secondary), based on input ~170 VDC bus to ~8-12 V secondary AC before rectification. Exact ratio is proprietary but can be measured by applying low-voltage AC (e.g., 5 VAC at 1 kHz) to the primary and measuring secondary voltage (ratio = V_primary / V_secondary).
Primary inductance: ~2-4 mH (measured at 120 kHz, no DC bias). Low inductance indicates core saturation or shorted turns.
Winding resistance (DCR):
Primary (pins 1-2): 20-50 Ω.
Main secondary (pins 6-7): 0.5-2 Ω.
Auxiliary secondary (pins 8-9): 0.2-1 Ω.
If DCR is infinite (open) or zero (shorted), replace the transformer.
Power rating: ~130 VA total (matches monitor max power draw).
Impedance regulation: <10% voltage drop at full load (90-264 VAC input). Test by loading secondaries (e.g., 1 A at +12 V) and measuring output ripple (<100 mV).
If the transformer is suspected faulty (common failure mode: overheats from bad snubbers or MOSFET), replacement part is 053X0631-001 (~$50 from arcade parts suppliers). Always recap the power supply (C101, C104-C107) and check for service bulletins (e.g., S04E0000-000F for PS upgrades) before swapping. For full schematic, refer to Wells Gardner service manual 069X2710-100 (includes power section with T101 details).